Hmmm. Sounds like suboptimal code, the idea that characters get created before the game knows whether they even matter (whether the player will in any way get to see the details). It would make more sense to say "There's two bandits over there, do you want to engage?" and then, if you engage, generating characters. This problem would be even worse for those giant packs of bandits I've seen (but not yet engaged with).
Actually, optimal code would likely generate a full character only upon capture, and generate a partial (necessary stats only) character for combat, then generate the next partial bit at the end of combat (when you get to see a few new stats), and finally transferring the partial character into a fresh full character if you capture them.
It's good to know that the uniqueness sticks around even if you sell them, though. That does avoid some issues.